Hot water boiler



March 30, 1965 M. DUBIN ETAL HOT WATER BOILER 2 Sheets-Sheet 1 FiledDec. 13, 1961 ATTO RNEY wk v. m wm W 3 m u 2 WDMWT a m m w n mmmfi Mmnmm m w M w x w 8 L LL his C, a 2 m i H \E n 1| 1 I. ll 9 W g m 1 3 H x44H I I I l l I l ll Ill l|I.l|\ A] i L H 1. 2 5 M M a M i m G .1 a 4 Su l W G 2 w F M REUEF VALVE March 30, 1965 M. DUBlN ETAL HOT WATERBOILER 2 Sheets-Sheet 2 Filed Dec. 13, 1961 FIG. 7 1; I

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m MN 0 v T Em MM Y A. NN V. 0| E 2 U T R 5 O W T MG T A "mm M NV ER BlUnited States Patent 3,175,540 HOT WATER BOILER Melvin Dubin, New York,and Milton Gordon, Levittown, N.Y., Benjamin Ronn, Palisades Park, N.J.,and Isidore Turinsky, North Babylon, N.Y., assignors to Slant/ FinRadiator Corporation, Richmond Hill, N.Y., a corporation of New YorkFiled Dec. 13, 1961, Ser. No. 159,129 7 Claims. (Ci. 122-230) Thepresent invention relates to boilers, particularly intended for centralheating in circulating hot-water systems but having additionalapplications.

From the point of view of fuel economy, it is desirable that a furnaceshould have a boiler that effectively extracts all the heat available inthe combustion gases. Carried to a limit, this could lead to immenseboilers of elaborate construction. However, the boiler installationshould conserve space and therefore a boiler of minimum size isdesirable, consistent with etficient heat extraction as evidenced by lowtemperature of the discharged fluegas, and consistent with the ratedheat-extraction capacity, that is, the amount of heat per hour that canbe delivered to the heating system. Minimum cost is also desirable andthis, in turn, is related both to the amount of material required and tothe character of the manufacturing operations required by the form ofthe boiler.

An object of this invention resides in the provision of a novel form ofboiler that combines high efliciency with compactness, for given ratedcapacity. A further and important object of the invention resides in theprovision of an efficient and compact boiler that is of a novelconfiguration providing extensive heat-exchange wall area from thecombustion-gas passages to the water space, without resort to shapes ordesigns which would necessitate costly or exacting manufacturingmethods. With particular concern for circulating hot-water heatingsystems, an object of the invention resides in provision of a novel formof boiler and combines the foregoing features with provision of anextended length of path of the water through the heat-exchange unit.

Hot water boilers for heating systems are generally made of cast-iron;and in order to provide extensive heat-exchange surfaces, elaborateshapes have been devised involving cavities that can be fashioned onlyby resort to cores in the casting process. Such a design has the efifectof increasing the cost of the castings, and of allowing undue wallthicknesses so as to take into account the limitations of themanufacturing methods, notably the variations in positioning of thecasting molds and cores. Excess wall thickness increases both the costand the weight of the cast-iron used, and it also increases the wallthickness through which the heat must travel from the combustion-gaspassages to the water. It is a feature of the novel heat-exchange unitprovided by the present invention that a minimum of wall thickness canbe attained without resort to special casting methods.

The foregoing and other objects of the invention are achieved in theillustrative embodiment and a modification that are described in detailbelow and are shown in the accompanying drawings. The preferredembodiment shown utilizes a pair of cast walls that incorporaterelatively numerous passages of large surface area exposed to the hotcombustion-gases and correspondingly numerous water spaces forextracting the heat. Casting cores are not needed in making the walls,which are sealed to each other. Despite the extensive heat-exchange areaprovided by formations in the walls, the two walls are joined to eachother only at their periphery. The joint is especially easily made andreliable in service when it is in the form of a circle. The walls havetapered 3,175,540 Patented Mar. 30, 1965 complementary circular sealingrims in the embodiment described below. Such rims may be cast to a highorder of precision without inordinate expense, and a circular taperedrim can be readily machined for ideal complementary fit, even to theextent of producing a wa ter-tight seal without resort to sealingcompounds.

The illustrative embodiment of the invention includes elongated zig-zagcombustion-gas passages that alternate, horizontally, with elongatedvertical zig-zag water spaces; and by proper arrangement of the waterinlet and water outlet sections of the boiler and interconnection of thevarious water spaces, remarkably efficient and effective boilerperformance is attained. For directing the flow of water through theheat-exchange unit, reliance is placed not only on the formations in thecast-iron walls of the heat-exchange unit, but in addition there isprovided a series of water-space dividers that have ears by which thedividers are resiliently centered in the respective water spaces. Thedividers are simply deposited in the respective water spaces, before thetwo walls are assembled together, and they retain their intendedpositions without resort to special fastening means and without resortto special mounting or sealing devices for the dividers.

The nature of the invention, and its further objects, novel features andadvantages will be more fully apparent from the following detaileddescription in which reference is made to the accompanying drawingswhich form part or" the present disclosure.

In the drawings:

FIG. 1 is the perspective of a hot water boiler;

FIG. 2 is a vertical section through the boiler of FIG. 1, as viewedfrom the line 2-2 in FIG. 6; H

FIG. 3 is an enlarged fragmentary perspective view of a component inFIG. 2; g

FIG. 4 is a horizontal cross-sectional view at the plane 4-4 of FIG. 2;

FIG. 5 is an exploded perspective, partly in crosssection, of certaincomponents in FIGS. 2, 3 and 4;

PEG. 6 is a vertical cross-section of the boiler in FIGS. 1, 2 and 4, asviewed generally from the line 66 in FIG. 2; and

FIG. 7 is a horizontal cross-section of a modification, viewedcorresponding to FIG. 4.

FIG. 1 shows the exterior of a hot-water boiler of a form that issuitable and intended for central heating of a home by circulating hotwater, as an illustrative application of various features of the presentinvention. The sheet-metal exterior 10 completely encloses theheatexchange unit and a gas burner, the walls of sheet-metal enclosure10 being suitably insulated internally, as by rock-wool. Combustion gasmay be supplied at gas-pipe 12, and the flue gas emerges via chimneypipe 14. .Water returns from the heating system and enters the boiler atinlet pipe 16. Heated water leaves the heat exchan'ge unit forrecirculation via outlet pipe 18. Another pipe 20 is shown, suitable fora temperature gage, a pressure gage, a pressure-relief valve, and anycombination of these devices and others in conventionalheating'installations.

In FIGS. 2, 4 and 6, the boiler 22 is shown, certain importantcomponents being shown in FIG. 5. Below the heat-exchange unit is a gasburner 23, divided into two sections as shown in FIGS. 2 and 4.Heat-exchange unit 22 includes two one-piece seamless walls 24 and 26 ofcast-iron that are joined together by a circular seal 28 formed bycomplementary circular rims integral with walls 24 and 26, with anappropriately tapered portion 28a. Walls 24 and 26 together form agenerally cylindrical or barrel-shaped unit with a horizontal axis.

In FIGS. 4, 5 and 6, wall 24 is seen to include formaears 46 providelateral plates 60 48 extend to" the floor and provide vertical tionsproviding four vertical zig-zag passages 30a, 30b, 30c and 30d for theburning of hot combustion gases,

or fiue gases. At the horizontal extremes, diametrically, at the leftand right of walls 24 and 26 as shown in FIG. 5, are water-containingsections 32 and 34 at the inlet and the outlet portions of theheat-exchange unit. These may-be considered to be inlet and outlet watermanifolds, distributing the water to different devices at the inlet andcollecting water from dilferent levels at the outlet side of theheat-exchange unit.

The formations in wall 24 between combustion-gas passages 30a, 30b, 30cand 30d, namely formations 36a, 36b and 36c,"constitute vertical'zig-zag water spaces. Referring to FIG. 4, formations 36a, 36b and 360are shown in horizontal cross-section, and appear as loops that aredirected outward relative to the internal water space. In this samehorizontal cross-section, loops 38a, 38b, 38c. and 38d are directedinward, relative to the water-containing space within walls 24 and 26.

The two walls 24 and 26 are essentially mirror-images of each other,disregarding such details as the complementary formations that formcircular seal 28. Accordingly, walls 24 and 26 have aligned inwardlydirected loops 38a, 38b, 38c and 38d, and correspondingly these Walls 24and26 have alignedoutwardly directed loops 36a, 36b and 360.

Within loops 36a, 36b and 360 of both walls 24 and 26 are three verticalzig-zag dividers 40a, 40b and 400 of sheet-metal, preferably stainlesssteel. Each of these sheet-metal members 40 has a series of. cut-outs,with 7 resulting edges 42 and legs 44, and each leg has opposite lydirected ears 46. The respectivedividers 40 are centered in thecorresponding vertical zig-zag water passages of formations 36a, 36b and36c by virtue of the bent ears 46; andlegs 44 insure substantial spacingbetween the edges 42 of the dividers and the extremities of the outwarddirected loops 36a, 36b and 3'60. Legs 44 and yielding or resilientlocating supports for the dividers Before the two walls are assembled,the dividers are dropped into place in one wall. After the walls areassembled, cars 46 engage the converging sur- I faces ofthe outwardloops to hold the dividers in position resiliently after the two wallsare assembled.

, A pair of vertical end plates 48 form lateral walls for ,thecombustion-gas passages 30a, 30b, 30c and 30d.

Flanking these end plates and aligned with the peripheral edges of walls24 and 26 are clamping rings 50. Tie rods 52 (threaded at their ends andprovided with nuts) hold vertical zig-zag combustion-gas passages fordelivery'to the flue-pipe 14, and ribs 56 provide abutment ledges fordirect the hot gases from burners 23 to the vertical zigzag passages. IPlates 60 and hoodfi58 extend horizontally all the way from one plate 48tothe other. These plates support for the heat-exchange unit. However,plates48 are exposed to'the hot combustion gases .and, both forefiicient opera 'tion and for insuring a cool exterior for enclosure 10,an

appropriate amount of heat insulation such as rock'wool '62 lines theinternal surface of sheet-metal enclosure V opposite plates 48, andelsewhere.

.-rings 50, vertical plates 48, and boiler-walls 24 and 26 in assemblyas illustrated. Ribs 54 provide abutment .ledges'for a hood 58 thatguides the flue gases from these which form a bottom fire chamber and asupply of domestic hot water.

16, ordinarily the return line of a circultaing hot-water heatingsystem. 7 Section 32 is of substantial vertical extent (noteparticularly FIG. 5) and acts as an inlet manifold to spread the inletwater up and down to various levels before the water starts to crossthrough the boiler to the outlet manifold section 34 and outlet line 18.Between sections 32 and 34, the 'water is caused to follow horizontalzig-zag pathsyas represented by the curved arrows in FIG. 4. Therelationship between the combustion-gas passages and the water flow asdescribed results in remarkably effective and efiicient extraction ofheat from the combustion gas and transferred to the hot water system.The temperature of the discharged flue gas is but little higher thanthat of the water at the oulet line 18. In a pracical example of such aboiler, a heat-exchange unit having walls 24 and 26 approximately 20inches in outside diameter by 13 inches in axial length has been shownin tests to yield an output of 80,000 Btu. per hour at efficiency.Accordingly, the device shown is both compact and highly eflicient, andis well suited to use in central heating systems.

The heat-exchange unit is of a construction that lends itself readily tolow-cost manufacture. As seen in FIG. 4 particularly, each of thewalls24 and 26 has surfaces everywhere that have a'minimum castingdraft-angle so as to be well suited to simple casting methods withoutresort to costly special cores or the like. This is true of the insideand outside surfaces of both walls, and is true even of ribs '64.Nevertheless, and particularly in view of the remarkably intimateheat-transfer relationship between the vertical zig-zag gas passages andthe horizontal zig-zag water passages, no more than a single'sirnplecircular water-seal is involved in joining the two walls 24 and26 together. Tapered surfaces 28a may have a machined finish, which isparticularly easy to provide where the seal is circular. It has beenfound practical to assemble walls 24 and 26 together without requiring asealing compound. Even where sealing compound is desired, the water sealinvolved in the illustrated walls 24 and 26' of the same general shapeas that in FIGS. 2, 4, 5 and 6, with a modified seal 28' and modifieddivider plates 46'. The configuration in FIG. 7 is significant in thatit incorporates a hot water heating tank 66. The apparatus in FIG. 7 isthus adapted to serve not only in a circulating hot-water heatingsystem, but also to provide domestichot water. Separate inlet and outletconnections are provided for the two water spaces at the opposite sidesof tank 66. It will be understood, of course, that unit 66 hasappropriate cold-water inlet and hot-water outlet lines (not shown). Itwill also be understood that the boiler of FIGS. 2, 4, 5 and 6 may beequipped with a conventional tankless coil for providing a Because unit66 as shown forms a complete barrier across the water-container, twowater paths exist, and two sets of pipes 16, 16' at the inlet and 18,18' at the outlet are provided Where greatly increased capacity isdesired, the units illustrated in the drawings maynot only be increasedin size for greater heat-exchange surface area, but additional boilers22 may be assembled in axial alignment. In that event, afiue-gas'passage 30 of one unit would be aligned with a like flue-gaspassage 30 of thenext axially aligned heat-exchange unit; andconsequently, no intervening plate 48 would be used at such confrontingflue-gas passages except, possibly, for providing support.

occur to those skilled in the art, in light of the foregoing disclosure.Consequently, the inventionshould be broadly construed in accordancewith its full spirit and scope.

What is claimed is: i i

1. A hot-water boiler, including a pair of confronting walls havingaligned sealing rims, said walls together defining a water-containingspace and having water-inlet and water-outlet connections, each of saidwalls having inward and outward extending corrugations therein providingmultiple outside vertically continuous zig-zag fluegas spacesalternating horizontally with multiple inside vertically continuouszig-zag Water spaces, each said zigzag water space being approximatelyequal to each said zig-zag flue gas space when viewed in transversecrosssection, the corrugations of said pair of walls having a combineddepth when measured along a horizontal line from one of said walls tothe other that is substantially greater than half of the maximumhorizontal extent of the water-containing space between said walls whenmeasured along said line, said outward extending corrugations of eachwall being coplanar, andmeans engaging said coplanar formations forlaterally closing off said flue gas spaces.

2. A hot-water boiler, including a pair of confronting walls, said wallstogether defining a water-containing space and having water-inlet andwater-outlet connections, each of said walls having inward and outwardextending formations therein providing multiple outside verticallycontinuous zig-zag flue-gas spaces alternating horizontally withmultiple inside vertically continuous zig-zag water spaces, said outwardextending formations of each wall being coplanar, means laterallyengaging said outward formations for laterally closing off said flue-gasspaces,

the transverse cross-section of each said flue-gas space being at leastapproximately equal to that of each said zig-zag water space, and theformations of said pair of walls having a combined extent when measuredalong a horizontal line from one of said walls to the other that issubstantially greater than half of the maximum horizontal extent of thewater-containing space between said walls when measured along said line,and vertical zig-zag sheet-metal dividers in a plurality of saidvertical zig-zag spaces, said walls and said dividers forming horizontalzig-zag spaces interconnecting said divided vertical zig-zag waterspaces.

3. A hot-water boiler, including a pair of confronting walls havingmating tapered circular sealing rims, said walls together defining awater-containing space and having water-inlet and water-outletconnections, each of said walls having inward and outward projectingformations therein providing multiple outside vertically continuouszig-zag flue-gas spaces alternating horizontally with multiple insidevertically continuous zig-zag water spaces, each said zig-zag waterspace being approximately equal to each said zig-zag flue-gas space whenviewed in transverse cross-section, the formations of said pair of wallshaving a combined extent when measured along a horizontal line from oneof said walls to the other that is substantially greater than half ofthe maximum horizontal extent of the water-containing space between saidwalls when measured along said line, said inward and outward projectingformations of each of said Walls being disposed at opposite sides of arespective vertical plane.

4. A hot-water boiler, including a pair of confronting walls havingaligned sealing rims, said walls together defining a water-containingspace and having water-inlet and water-outlet connections, each of saidwalls having outward and inward formations therein disposed alternatelyat opposite sides of a vertical plane providing multiple outsidevertically continuous zig-zag flue-gas spaces alternating horizontallywith multiple inside vertically continuous zig-zag water spaces, saidzig-zag water spaces and said zig-zag flue-gas spaces beingsubstantially equal when viewed in transverse cross-section, saidformations of said pair of walls being greater in extent when measuredalong a horizontal line from one of said walls to the other than half ofthe extent of said watercontaining space between said walls whenmeasured along that line, each said wall having sloping surfacesproviding a forming draft-angle throughout in opposite directionsrelative to said sealing rims.

5. A hot-water boiler, including a pair of confronting walls havingaligned sealing rims, said walls together defining a water-containingspace and having water-inlet and water-outlet connections, each of saidwalls having formations therein providing multiple outside verticallycontinuous zig-zag flue-gas spaces alternating horizontally withmultiple inside vertically continuous zig-zag water spaces, said zig-zagwater spaces and said zig-zag flue-gas spaces being approximately equalwhen viewed in transverse cross-section, the formations of said pair ofwalls having a combined extent when measured along a horizontal linefrom one of said walls to the other that is substantially greater thanhalf of the maximum horizontal extent of the water-containing spacebetween said walls when measured along said line, said formations ofeach of said walls extending outward to a respective common plane, and aplate against the outward extending formations of each of said Walls,respectively, laterally closing off said flue-gas spaces.

6. A hot-water boiler, including a unitary seamless heat-exchange wallhaving formations affording a series of vertically continuous flue-gasspaces separated by vertically continuous zig-zag water-containingspaces whose cross-section approximates that of the flue-gas spaces, thehorizontal cross-section through said formations presenting a series ofconnected loops extending alternately outward and inward relative to thewater-containing space and the outward extending formations beingcoplanar, the flue-gas spaces being constituted by the spaces betweensaid outward loops, means confronting the successive inward loops butspaced therefrom by less than the inward-to-outward extreme portions ofsaid formations, and said last-named means having a tapered circular rimsealed to a complementary peripheral edge of said heatexchange wall,said last-named means providing a confronting wall for saidheat-exchange wall, and means laterally engaging said coplanar outwardextending formations for laterally closing off said flue-gas spaces.

7. A hot-water boiler, including a generally barrelshaped heat-exchangeunit disposed with its axis extending horizontally and having twoconfronting individually seamless heat-exchange walls havingcomplementary tapered circular rims and sealed to each other only atsaid rims, said walls together defining a water-containing space andhaving water-inlet and water-outlet connections, each of said wallshaving inward and outward extending formations therein providingmultiple outside vertically continuous zig-zag flue-gas spacesalternating horizontally with multiple inside vertically continuouszigzag water spaces, said zig-zag water spaces and said zigzag flue-gasspaces being approximately equal when viewed in transversecross-section, said formations of said pair of walls having a combinedextent when measured along a line extending horizontally from one ofsaid walls to the other that is substantially greater than half thehorizontal extent of said water-containing space between said walls whenmeasured along said line, said outward extending formations of saidwalls extending to a pair of vertical planes, respectively, and a pairof plates laterally closing off said flue-gas spaces and engaging saidoutward extending formations, respectively, said plates being secured tosaid walls and extending below said walls and constituting supportingmeans for said walls.

(References on following page) References Cited by the Examiner UNITEDSTATES PATENTS Lapp 122-228 Dickinson 122-227 5 Gieseler 122-367 X Sharp122-210 Jungers 122-225 Ofeldt 122-408 X FOREIGN PATENTS 3/26 France; I

1/ 29 Great Britain. 9/40 Great Britain.

PERCY L. PATRICK, Primary Examiner. Franzheim 122-210 10 FREDERICK L.MATTESQN, JR., Examiner.

1. A HOT-WATER BOILER, INCLUDING A PAIR OF CONFRONTING WALLS HAVINGALIGNED SEALING RIMS, SAID WALLS TOGETHER DEFINING A WATER-CONTAININGSPACE AND HAVING WATER-INLET AND WATER-OUTLET CONNECTIONS, EACH OF SAIDWALLS HAVING INWARD AND OUTWARD EXTENDING CORRUGATIONS THEREIN PROVIDINGMULTIPLE OUTSIDE VERTICALLY CONTINOUS ZIG-ZAG FLUEGAS SPACES ALTERNATINGHORIZONTALLY WITH MULTIPLE INSIDE VERTICALLY CONTINUOUS ZIG-ZAG WATERSPACES, EACH SAID ZIGZAG WATER SPACE BEING APPROXIMATELY EQUAL TO EACHSAID ZIG-ZAG FLUE GAS SPACE WHEN VIEWED IN TRANSVERSE CROSSSECTION, THECORRUGATIONS OF SAID PAIR OF WALLS HAVING A COMBINED DEPTH WHEN MEASUREDALONG A HORIZONTAL LINE FROM ONE OF SAID WALLS TO THE OTHER THAT ISSUBSTANTIALLY GREATER THAN HALF OF THE MAXIMUM HORIZONTAL EXTENT OF THEWATER-CONTAINING SPACE BETWEEN SAID WALLS WHEN MEASURED ALONG SAID LINE,SAID OUTWARD EXTENDING CORRUGATIONS OF EACH WALL BEING COPLANAR, ANDMEANS ENGAGING SAID COPLANAR FORMATIONS FOR LATERALLY CLOSING OFF SAIDFLUE GAS SPACES.